Baran M. F., Tümen V., Ekinci S., Özaydin M., Eftekhari A., Levent A., ...More
MAGNETOCHEMISTRY, vol.12, no.10, pp.1-20, 2026 (SCI-Expanded, Scopus)
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Publication Type:
Article / Article
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Volume:
12
Issue:
10
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Publication Date:
2026
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Doi Number:
10.3390/magnetochemistry12100111
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Journal Name:
MAGNETOCHEMISTRY
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Journal Indexes:
Applied Science & Technology Source, Scopus, Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest), Science Citation Index Expanded (SCI-EXPANDED), INSPEC, Directory of Open Access Journals
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Page Numbers:
pp.1-20
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Open Archive Collection:
AVESIS Open Access Collection
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Bursa Uludag University Affiliated:
Yes
Abstract
The growing demand for sustainable and high-performance energy storage systems has stimulated the development of biomass-derived electrode materials for supercapacitors. In this study, activated carbon (Cm-AC) was synthesized from Crataegus monogyna seeds and combined with magnetic iron oxide (Fe3O4) nanoparticles to fabricate a hybrid Cm-AC@Fe3O4 electrode. The incorporation of iron oxide into the activated carbon matrix altered the charge-storage mechanism from predominantly electrical double-layer capacitance to a hybrid process with a significant faradaic (diffusion-controlled) contribution. Electrochemical measurements in 1 M Na2SO4 showed that the specific capacitance increased from 145.92 to 270.68 F g−1 at a scan rate of 5 mV s−1. Dunn kinetic analysis revealed that diffusion-controlled faradaic processes accounted for up to 87.82% of the total capacitance at low scan rates, consistent with a dominant contribution from reversible Fe2+/Fe3+ redox reactions. Galvanostatic charge–discharge analysis yielded a specific capacitance of 351.51 F g−1 at 0.5 A g−1, while electrochemical impedance spectroscopy demonstrated reduced internal and charge-transfer resistances after Fe3O4 incorporation. A symmetric Cm-AC@Fe3O4 supercapacitor retained 87.5% of its initial capacitance after 10,000 charge–discharge cycles and delivered a maximum energy density of 10.35 Wh kg−1 at a power density of 396 W kg−1. These findings demonstrate that biomass-derived Cm-AC@Fe3O4 is a promising and sustainable electrode material for high-performance supercapacitor applications.